The aim of this book is to initiate you into the world of GNU/Linux. It covers the basics of the free software, how to use and modify GNU/Linux to suit your needs, and how to find your way in this new world more easily. Nonetheless, this document is not an essential reference guide for administrators and/or users; there are already hundreds of manuals, how-to guides and other reference works numbering thousands of pages that serve this purpose. Our aim here is to help you take your first steps in this as-yet uncharted territory for too many users and administrators, and to explain how to tackle and resolve potential problems by yourself.

The Book is not based on any particular distribution, but we need to specify certain actions for most of the examples and activities, for which we will use Debian GNU/Linux. Although this distribution is not as intuitive and user-friendly as others, it will serve to explain all the characteristics of a GNU/Linux-based operating system, step by step.